CN108768127A - A kind of composite stepper motor - Google Patents

Abstract

The invention discloses a kind of composite stepper motors, including rotor, stator and winding, the rotor is placed in the stator, and there are the stator multiple magnetic poles, the winding to be placed on the magnetic pole, and permanent magnetic steel is embedded on the stator.Sinusoidal rule variation is presented in the composite stepper motor zero load magnetic linkage of the present invention and unloaded back-emf, having except the advantages that precision is high, torque is big, greatly simplifie the structure of rotor, enhance the strength and stability of rotor, to improve the reliability of composite stepper motor, the applicable working condition and application range of motor are expanded.

Description

A hybrid stepper motor

technical field

The invention relates to the field of hybrid stepping motors, and in particular relates to the body design of the hybrid stepping motor.

Background technique

Stepper motors have been widely used in various fields of production and life due to their open-loop control, good positioning accuracy, low price, easy start and stop, forward and reverse rotation, no accumulated error, and self-locking function. Especially the hybrid stepper motor has good application prospects due to its advantages of high resolution, large torque and stable temperature characteristics.

The traditional hybrid stepper motor is divided into rotor, stator, magnetic steel, winding and other parts. The magnetic steel is placed in the rotor, and the winding is wound in the stator slot. It has axial excitation and radial excitation sources. If there is no magnet steel on the rotor, the motor will not generate torque if it is only energized in the control winding of the stator; if the stator winding is not energized, it will only have the effect of the rotor magnet steel, and the motor will basically not generate torque; only when the rotor magnet steel and Electromagnetic torque is produced only under the interaction of stator magnetic potential. Therefore, the hybrid stepper motor must have a permanent magnet, so that half of the rotor core is positive and the other half of the rotor core is negative.

Hybrid stepper motors are only used in low-speed, low-precision open-loop systems at first, and are increasingly used in wide-speed, high-precision servo control systems in recent years, which also requires stepper motors to have better Excellent high-speed performance and start-stop performance. However, permanent magnetic steel is placed in the middle of the rotor core, which reduces the reliability of the rotor part and is not conducive to the stability of the magnetic steel sheets.

Contents of the invention

The present invention is contemplating this, and provides a new type of hybrid stepping motor, which improves the reliability of the rotor part and solves the technical problems of the traditional stepping motor under high-speed rotation, frequent start-stop and other working conditions.

The invention provides a hybrid stepping motor, which includes a rotor, a stator and a plurality of windings, the rotor is placed in the stator, the stator has a plurality of magnetic poles, each of the windings is respectively placed in each On each of the magnetic poles, permanent magnets are embedded on the stator.

In a specific embodiment of the present invention, preferably, the rotor includes a first rotor core and a second rotor core, the surfaces of the first rotor core and the second rotor core have small teeth, and the surface of the first rotor core The small teeth and the small teeth of the surface of the second rotor core have the same pitch, but are offset from each other by half the pitch.

In a specific embodiment of the present invention, preferably, the rotor further includes a connecting disk, the connecting disk is placed between the first rotor core and the second rotor core, the material of the connecting disk is the same as that of the The first rotor core is the same as the second rotor core, and has a smaller radius than the first rotor core and the second rotor core.

In a specific embodiment of the present invention, preferably, the magnetic poles are provided with a plurality of small teeth, and the pitch of the small teeth is the same as that of the small teeth on the rotor.

In a specific embodiment of the present invention, preferably, the stator includes a first stator core and a second stator core, and the first stator core and the second stator core have the same shape and are symmetrical in position.

In a specific embodiment of the present invention, preferably, the permanent magnet is placed between the first stator core and the second stator core.

In a specific embodiment of the present invention, preferably, the first stator core and the second stator core are provided with magnetic poles, and together constitute the magnetic poles of the stator.

Beneficial effects, the no-load flux linkage and no-load back electromotive force of the hybrid stepper motor of the present invention both present a sinusoidal change, and besides the advantages of high precision and large torque, the structure of the rotor is greatly simplified and the rotor is enhanced. The strength and stability of the hybrid stepper motor improve the reliability of the hybrid stepper motor and expand the applicable working conditions and application range of the hybrid stepper motor.

In order to make the above-mentioned features and advantages of the invention more comprehensible, the following specific embodiments are described in detail together with the accompanying drawings.

Description of drawings

Figure 1 is a perspective view of the hybrid stepping motor of the present invention.

FIG. 2 is an exploded view of the rotor 1 and the stator 2 of the hybrid stepping motor in FIG. 1 .

FIG. 3 is a top view of the hybrid stepping motor of the present invention in FIG. 1 .

Fig. 4 is a perspective view of the rotor of the hybrid stepping motor of the present invention.

Fig. 5 is another embodiment of the hybrid stepping motor of the present invention.

Detailed ways

In order to make the purpose and technical solutions of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiments of the present invention. Apparently, the described embodiments are some, not all, embodiments of the present invention. Based on the described embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

As shown in FIG. 1 and FIG. 2 , it is a hybrid stepping motor of the present invention. The hybrid stepping motor includes a rotor part 1 and a stator part 2 , and the rotor part 1 is placed inside the stator part 2 .

The rotor part 1 , as shown in FIG. 2 , includes a rotor core 11 , a rotor core 13 and an engaging disc 12 , and the engaging disc 12 is placed between the rotor core 11 and the rotor core 13 . The connecting disc 12 is a magnetically permeable disc without cogged structure, and is used for connecting the rotor cores 11 and 13 . The connecting disk 12 is made of laminated silicon steel sheets of the same material, and its radius is smaller than that of the rotor cores 11 and 13, mainly having the functions of magnetic conduction, connection and reduction of magnetic flux leakage.

As shown in Fig. 4 again, there are fifty small teeth on the rotor core 11 and the rotor core 12 respectively, and other numbers of teeth are also possible, but it must be ensured that the tooth pitches of the stator and the rotor are the same. The more teeth, the smaller the step angle, and the higher the precision of the stepping motor. In addition, the small teeth 111 on the rotor core 11 and the small teeth 131 on the rotor core 13 are staggered by half the pitch from each other, that is, there is a phenomenon of staggered teeth.

The stator part 2 includes a permanent magnet 22 , a stator core 21 , and a stator core 23 , and the permanent magnet 22 is placed between two sections of the stator core 21 and 23 . The permanent magnetic steel 22 is axially magnetized.

On the premise of not changing the working principle and motor performance, the motor structure can be further simplified to the motor structure shown in FIG. 5 , and eight sections of permanent magnetic steel bars 22 are embedded in the stator 2 to reduce the cost of the motor.

As shown in FIG. 3 , the stator core 21 includes eight magnetic poles 211 - 218 , and each magnetic pole has six small teeth 2111 . The stator core 22 also has the same structure, and the stator core 21 and the stator core 22 are placed symmetrically, and there is no wrong tooth between them.

Referring to FIG. 4 and FIG. 3 , the pitches of the small teeth 121 on the rotor core 11 and the rotor core 12 and the small teeth 2111 on the stator cores 21 and 23 are the same. A winding 3 is wound around each pole 211-218. The winding 3 adopts a concentrated winding to generate a radial magnetic field, which forms a synthetic magnetic field with the axial magnetic field of the permanent magnet 22 .

As shown in FIG. 3 , it is a two-phase hybrid stepping motor. The stator 21 has two-phase eight poles, and the spaced magnetic poles are in the same phase. The magnetic poles 211, 213, 215, and 217 are phase A, and the magnetic poles 212, 214, 216, and 218 are phase B. Among the four magnetic poles 211, 213, 215, and 217 of the same phase, the poles of the two opposite magnetic poles 211 and 215 The polarities are the same, the polarities of the magnetic poles 213 and 217 are the same, and the two non-opposite magnetic poles, for example, the polarities of the magnetic poles 211 and 213 are opposite.

Due to the staggered tooth phenomenon between the upper and lower sections of the iron core 11 and 13 of the rotor 1, when the winding 3 on the A phase is energized, the air gap permeability of the stator A phase opposite to the rotor iron core 11 is the largest, and the rotor iron core 13 is opposite to the stator. The air gap permeance is the smallest under phase A. When the rotor 1 rotates, the lower air gap permeance corresponding to the rotor core 11 decreases, the lower air gap permeance corresponding to the rotor core 13 increases, and the total permeance on the main magnetic circuit basically remains unchanged. Similarly, the same is true when the windings 3 on other phases are energized. The staggered tooth structure of the two rotor cores 11 and 13 makes the hybrid stepper motor not rotate under the action of only electric excitation.

If there is no magnetic steel 22 on the stator 2, but the winding 3 is energized alternately according to a certain rule, the motor will not produce torque. If the winding 3 is not energized, there is only the effect of the magnetic steel 22, and the hybrid stepping motor basically does not generate torque. After the magnetic steel 22 of the two-phase hybrid stepping motor is axially magnetized, one end is an N pole, and the other end is an S pole. The magnetic field forms a closed loop along the stator irons 21 and 23 , the air gap, and the rotor cores 11 and 13 . Within the scope of each magnetic pole on this magnetic circuit, because the teeth of the two rotors are staggered, when the magnetic permeability at one end increases, the magnetic permeability at the other end will inevitably decrease. The total permeance basically remains unchanged when the position of the rotor 1 is different, so the total permeance of the entire magnetic circuit has nothing to do with the position of the rotor 1 .

Therefore, only under the combined action of the electric excitation of the winding 3 and the permanent magnet of the magnetic steel 22, the electromagnetic torque will be generated. When the magnetic steel 22 is magnetized and the winding 3 on the phase A magnetic pole is energized, the rotor 1 has a certain stable equilibrium position, that is, the tooth-to-tooth position of the stator and the rotor. The electromagnetic torque received by the two rotor cores is in the same direction, which is the direction to make the rotor return to the current stable equilibrium position. This is because at both ends of the motor, the polarity of the stator 2 is the same, and the polarity of the rotor 1 is opposite, but they are staggered by half the tooth pitch, so when the rotor 1 deviates from the stable equilibrium position, the direction of the acting torque at both ends is the same. The stable equilibrium position of the hybrid stepping motor is that the magnetic permeability under the polarity of the stator and rotor is the largest, and the magnetic permeability under the pole of the same polarity is the smallest.

When switching to the winding 3 on the B-phase magnetic pole, there will be a new stable equilibrium position, that is, the tooth-to-tooth position of the stator and rotor under the B-phase magnetic pole. At this time, the rotor 1 will rotate to a new stable equilibrium position under the action of the electromagnetic torque. In this way, the forward A phase, forward B phase, reverse A phase, and reverse B phase are alternately passed through alternately, and the two-phase new hybrid stepping motor will rotate like this.

The present invention adopts the above-mentioned technical scheme, and has the following beneficial effects:

Since the present invention places the permanent magnet steel 22 on the stator 2, the structure of the rotor 1 is greatly simplified, the strength and stability of the rotor 1 are enhanced, thereby improving the reliability of the motor and expanding the applicable working conditions and application range.

Both the winding 3 and the permanent magnet steel 22 of the present invention are located on the stator, which greatly simplifies the rotor structure.

Both the no-load flux linkage and the no-load back EMF of the motor of the present invention show sinusoidal changes, and besides the advantages of high precision and large torque, the structure of the rotor is greatly simplified, and the strength and stability of the rotor are enhanced, thereby The reliability of the motor is improved, and the applicable working conditions and application range of the motor are expanded.

Although the present invention has been disclosed as above with the embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field can make some changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be defined by the scope of the appended patent application.

Claims (7)

1. a kind of composite stepper motor, including, a rotor, a stator and multiple windings, the rotor are placed in the stator, There are the stator multiple magnetic poles, each winding to be respectively placed on each magnetic pole, which is characterized in that on the stator Embedded with permanent magnetic steel.

2. a kind of composite stepper motor as described in claim 1, which is characterized in that the rotor include the first rotor iron core, The surface of second rotor core, the first rotor iron core and the second rotor core has small tooth, and the table of the first rotor iron core The small tooth tooth pitch having the same of the small tooth in face and the surface of the second rotor core, but be offset from each other half tooth away from.

3. a kind of composite stepper motor as claimed in claim 2, which is characterized in that the rotor also includes a linking disk, The linking disk is placed between the first rotor iron core and the second rotor core, it is described linking disk material with described first turn Sub- iron core and the second rotor core are identical, and the radius of radius ratio the first rotor iron core and the second rotor core is small.

4. a kind of composite stepper motor as claimed in claim 2, which is characterized in that the magnetic pole is equipped with multiple small teeth, institute The tooth pitch for stating small tooth is identical as the tooth pitch of small tooth on the rotor.

5. a kind of composite stepper motor as described in claim 1, which is characterized in that the stator include the first stator core and Second stator core, first stator core and the second stator core shape same position are symmetrical.

6. a kind of composite stepper motor as claimed in claim 5, which is characterized in that it is fixed that the permanent magnetic steel is placed in described first Between sub- iron core and the second stator core.

7. a kind of composite stepper motor as claimed in claim 5, which is characterized in that first stator core and the second stator Iron core is equipped with magnetic pole, and collectively forms the magnetic pole of the stator.